IGCSE Computer Science 0478: The Complete Preparation Guide
IGCSE Computer Science (0478) is a two-paper, all-exam subject on the current syllabus for exams through 2026, 2027 and 2028. There is no coursework: every mark comes from Paper 1 and Paper 2, and the two papers reward different kinds of preparation. This guide maps the assessment, then lays out a revision sequence that fits how the marks are actually distributed.
The exam at a glance
| Paper 1 | Paper 2 | |
|---|---|---|
| Name | Computer Systems | Algorithms, Programming and Logic |
| Topics | 1–6 | 7–10 |
| Format | Short-answer + structured questions | Short-answer + structured questions |
| Duration | 1 hour 45 minutes | 1 hour 45 minutes |
| Marks | 75 | 75 |
| Compulsory? | Yes — all questions | Yes — all questions |
Both papers are equal in marks and time. Candidates answer on the question paper itself — no essay booklets, no multiple choice. Every question is compulsory, so there is no “avoid your weak topic” strategy; there is only “fix your weak topic”.
What each paper feels like
Paper 1 (Computer Systems) is the theory of how computer systems work — how data is represented, how hardware and software interact, how systems connect and the consequences of using them. Marks come in short definitional bursts and longer structured answers where exact terminology decides credit. It reads like a science paper: precise vocabulary, precise phrasing.
Paper 2 (Algorithms, Programming and Logic) is the problem-solving half: designing algorithms, writing and tracing pseudocode, reading flowcharts, and applying logic — including logic-gate problems. Crucially, the exam does not require one specific programming language: Cambridge defines its own pseudocode conventions, publishes the flowchart symbols, and expects you to think in that notation. The syllabus document itself contains the pseudocode and command-word reference sections — meaning the examiner publishes significant parts of the “language” you must answer in.
The strategy most students get wrong
Two failure patterns dominate 0478 preparation:
- Treating Paper 2 like a programming course. Students who only write real Python (or another language) arrive fluent in code but fluent in the wrong notation — writing
PRINTwhere Cambridge wantsOUTPUT,=where the arrow←is expected. The fix is drilled pseudocode fluency; our pseudocode rules reference condenses the conventions that cost the most marks. - Reading Paper 1 instead of retrieving it. Theory feels “done” when it is merely familiar. Paper 1 pays on recall under time — definitions, names of components, exact sequences. Active recall drilling (flashcards, self-quizzing, instant-feedback practice) is worth several hours of re-reading.
A revision sequence that targets the marks
- Start every topic with the syllabus wording. 0478 has crisp assessment objectives; a study note that paraphrases them loosely will under-serve the structured questions.
- Alternate the strands weekly. One Paper 1 topic + one Paper 2 skill per cycle keeps both papers moving and mirrors the equal mark weighting.
- Trace, then write. For algorithms: first trace given pseudocode line by line (state variable values after each pass), then write your own. Tracing is a Paper 2 question type in itself.
- Time-box full papers early. With two 1h45 papers, pacing is trainable: sit one full past paper per fortnight from mid-course, not only at the end.
- Mark your own structured answers against mark-scheme wording. The gap between “correct idea” and “mark-scheme phrase” is exactly where Paper 1 marks hide.
Coming from, or heading to, other routes
0478 overlaps heavily with the theory side of HKDSE ICT — students sitting both will find data representation and networks transfer directly. Heading onward, IGCSE CS is the natural runway into IB DP Computer Science; our IB CS guide shows what changes at DP level.
Where we come in
Distinction Academy teaches IGCSE Computer Science 0478 online and in-person across Hong Kong — theory drilling, pseudocode fluency and past-paper technique, supported by our smart practice system (instant-feedback drills, free with classes) and IGCSE notes and sample packs. Browse the subjects page or message us about a trial lesson.